WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Department of Information Engineering University of Padova, ITALY A Soft-QoS Scheduling Algorithm for Bluetooth Piconets A note on the use of these ppt slides: We’re making these slides freely available to all, hoping they might be of use for researchers and/or students. They’re in PowerPoint form so you can add, modify, and delete slides (including this one) and slide content to suit your needs. In return for use, we only ask the following: If you use these slides (e.g., in a class, presentations, talks and so on) in substantially unaltered form, that you mention their source. If you post any slides in substantially unaltered form on a www site, that you note that they are adapted from (or perhaps identical to) our slides, and put a link to the authors webpage: Thanks and enjoy! A note on the use of these ppt slides: We’re making these slides freely available to all, hoping they might be of use for researchers and/or students. They’re in PowerPoint form so you can add, modify, and delete slides (including this one) and slide content to suit your needs. In return for use, we only ask the following: If you use these slides (e.g., in a class, presentations, talks and so on) in substantially unaltered form, that you mention their source. If you post any slides in substantially unaltered form on a www site, that you note that they are adapted from (or perhaps identical to) our slides, and put a link to the authors webpage: Thanks and enjoy!

Department of Information Engineering University of Padova, ITALY A Soft-QoS Scheduling Algorithm for Bluetooth Piconets {andrea.zanella, daniele.miorandi, silvano.pupolin, Andrea Zanella, Daniele Miorandi, Silvano Pupolin, Andreola Cristian WPMC 2003, October 2003 Special Interest Group on NEtworking & Telecommunications

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Outline of the contents  Motivations & Purposes  Bluetooth Basic  Soft-QoS for Bluetooth: SFPQ  Simulations Result  Concluding Remarks

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 What and Why… Motivations & Purposes

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Motivations  Demand for QoS support over portable electronic devices is increasing:  audio/video streaming  interactive games  multimedia

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Hard & Soft QoS  Widely used in wired networks  Integrated Services: flow based (RSVP)‏  Differentiated Services: class based  Suitable for wireless networks  Applications may work even if, for short periods of time, QoS requirements are not satisfied  Deals with limited bandwidth and radio channel Hard-QoS Soft-QoS

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003  QoS parameters required per link  Minimum peak band: B r  End-to-End Delay: D r Target Satisfaction index  Soft QoS parameter: Target Satisfaction index   r = percentage of pcks expected to satisfy QoS constrains wealthy  r = 1  hard QoS (or “wealthy” clients)‏ poor  r = 0  pure best-effort (or “poor” clients)‏ Soft-QoS parameters

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Aim of the study  Adding Soft-QoS support to BT piconets  Design of Soft-QoS scheduling algorithm  Analysis of the proposed algorithm

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 What the standard says… Bluetooth basic

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Bluetooth piconet piconet  Two up to eight Bluetooth units sharing the same channel form a piconet  In each piconet, a unit acts as master, the others act as slaves centralized polling scheme  Channel access is based on a centralized polling scheme Time-division- duplex  Full-duplex is supported by Time-division- duplex (TDD), with time slots of T=0.625 ms active slave master parked slave standby slave1 slave2 slave3 master

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Introduction to QoS issues QoS in Bluetooth networks

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Hard QoS: the FPQ* scheme  QoS parameters required per link  Expected Data Rate  Maximum acceptable Delay  Limits  Inefficient short-period service differentiation  Slave Analyzer determines  Probability of queued packets (P data )‏  Time interval since last POLL/NULL  Selection Algorithm  Determine priority for each link  Select the link with highest priority *[Lapeyrie, Turletti, Fair and efficient Polling algorithm with QoS support,INFOCOM03]

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Soft QoS support Soft-FPQ algorithm for Bluetooth piconets

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Soft-QoS: the SFPQ scheme  Strategy  Dynamic estimation of the satisfaction level of each link  Adjust priorities according to Traffic characteristics Classic QoS parameters (max delay, min data rate)‏ Estimated Satisfaction Margins:

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Example of dynamic estimation

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Priority Evaluation Constants:  Traffic Demand  QoS Request Fairness Normalized Satisfaction Index

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 NS2 Simulation Simulation of QoS Bluetooth Piconet

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Simulation Scenario  Piconet with 7 slaves  Only upstream traffic  One application per slave  One application  =1 (Hard QoS)‏  One application  =0.9  One streaming video application  =0.9  4 Best Effort applications  =0.2  Simulation dynamic  Slaves with high  are active for all the simulation time  Best Effort transmissions start sequentially seconds apart  When all the applications are active the system gets close to saturation

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Satisfaction perceived (1/3)‏ Target Satisfaction:  =1 Heavy Load

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Satisfaction perceived (2/3)‏ Target Satisfaction:  =0.9 Heavy Load

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Satisfaction perceived (3/3)‏ Target Satisfaction:  =0.2 Heavy Load

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Delay Distribution  Video Streaming Delay Distribution  Low traffic  Video Streaming Delay Distribution  High traffic

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Conclusions & Future work  In summary, we have  introduced the Satisfaction Index parameter  proposed a method to dynamically estimate the perceived satisfaction  modified the priorities computation to take into account satisfaction margins  In other words, we have provided Soft QoS in Bluetooth  Better service differentiation  Efficient resource distribution  Next steps  Dynamic parameters tuning  Extension of the algorithm to Scatternet structures

WPMC 2003 Yokosuka, Kanagawa (Japan) October 2003 Department of Information Engineering University of Padova, ITALY A Soft-QoS scheduling algorithm for Bluetooth piconets Andrea Zanella, Daniele Miorandi, Silvano Pupolin, Andreola Cristian Questions?